Substrate transport means for skin packaging machines

ABSTRACT

A flat apertured endless belt has an upper stretch riding on air intake grills. Its apertures register with the air intakes to apply suction to the underside of substrate on it. Substrate lengths are impositively driven toward said stretch, faster than it moves, along a feed table having its top surface parallel to but above that of said stretch. Downstream from the table a hold down finger forces the medial portion of each substrate length into tractive engagement with the belt while its side edge portions are supported by rails coplanar with the table top, bowing it to an upwardly concave transverse curvature which insures that the length behind it will edgewise abut it.

United States Patent Schuette [54] SUBSTRATE TRANSPORT NIEANS FOR SKINPACKAGING MACHINES [72] Inventor: Thomas L. Schuette, Osseo, Minn.

[73] Assignee: Possis Machine Corporation, Minneapolis,

Minn.

[22] Filed: Nov. 2, 1970 [21] Appl. No.: 85,914

[52] U.S.Cl. ..53/1l2 A,53/l40, 271/74 [51] Int. Cl... ..B65b 35/28 [58]Field ofSearch ..53/140, 22 A, 112A; 271/74 [56] References Cited UNITEDSTATES PATENTS 3,533,212 10/1970 Borel et a1. ..53/10 X 2,927,409 3/19603,477,558 11/1969 Heyer Fleischauer ..271/74 X 1 1 July 18,1972

Gutierrez ..27l/74 X 3,172,526 3/1965 Buccicone ..l98/4l PrimaryExaminerTravis S. McGehee Attorney-Ira Milton Jones [57] ABSTRACT A fiatapertured endless belt has an upper stretch riding on air intake grills.Its apertures register with the air intakes to apply 1 suction to theunderside of substrate on it. Substrate lengths are impositively driventoward said stretch, faster than it moves, along a feed table having itstop surface parallel to but above that of said stretch. Downstream fromthe table a hold down finger forces the medial portion of each substratelength into tractive engagement with the belt while its side edgeportions are supported by rails coplanar with the table top, bowing itto an upwardly concave transverse curvature which insures that thelength behind it will edgewise abut it.

14 Claims, 9 Drawing Figures PATENTED JUL1 |972 3,676,979

SHEET u or 4 Thuzzzasl. 501m SUBSTRATE TRANSPORT MEANS FOR SKINPACKAGING MACHINES This invention relates generally to improvements inmachines for skin packaging, and is concerned moreparticularly withimproved means in such a machine for advancing substrate material, suchas paperboard, past successive processing stations at one of which afilm of thermoplastic skin forming substance may be deposited over thesubstrate material and at another of which suction may be applied to theunderside of the substrate material to draw the film down into snugengagement therewith.

One form of skin packaging machine is disclosed in the copendingapplication of Melvin J. Straub and myself, Ser. No. 842,99l,filed July18, 1969 now US. Pat. No. 3,596,432 and assigned to the assignee hereof.In that machine a continuous length or web of a substrate material suchas paperboard is unwound from a coil thereof on a supply reel and isadvanced along a defined path, past a loading station at which articlesto be packaged are placed on it at lengthwise spaced intervals. Next itmoves past a coating station at which a film of molten thermoplasticmaterial issues from a nozzle onto the articles and the substrate. Asthe web continues to advance, and before the thermoplastic film hashardened, the film is sucked down into snug engagement with the articlesand the top surface of the substrate material around them by theapplication of suction to the underside of the substrate, to draw airthrough pores or small apertures in it. The substrate finally moves to acutting station at which it is cut into discrete lengths, eachcomprising an individual package.

Prior skin packaging machines in which the film material was applied inmolten form were mainly confined to use with continuous lengths ofsubstrate, because the use of such machines with discrete lengths ofsubstrate posed certain problems that had not heretofore been solvedsatisfactorily. With a continuous web, the air intake at which suctionis applied is at all times covered by substrate, so that good suction isassured. But with short lengths, any interval or gap between adjacentpieces traversing the suction intake would afford a large air intakeopening which could soreduce suction that air could not be drawn throughthe substrate to suck down the film.

On the other hand, if thin, fiat pieces of paperboard or the like areurged edgewise toward one another in an effort to prevent gaps betweenthem, they tend to slide up onto one another, into a partially maskingrelationship that prevents deposition of film on portions of their topsurfaces.

It is of course desirable that a skin packaging machine be adaptable foruse with substrate material that is in either continuous strip form ordiscrete lengths, in order for the machine to have the maximum utility;and with this in mind it is an object of the present invention toprovide means enabling a skin packaging machine to accommodate discretelengths of substrate material as well as continuous strip or webs orsubstrate material.

It is another object of this invention to provide a skin packagingmachine that can be operated with either pre-cut or continuous websubstrates, and can be readily adjusted to accommodate substrates ofsubstantially different widths without loss of suction when the narrowersubstrates are used.

Another and more specific object of this invention is to providetransport means for advancing substrate material (either precut orcontinuous) from station to station through a skin packaging machine,and wherein suction applied to the underside of the substrate materialnot only evacuates the space beneath a thermoplastic film thereon butalso draws the substrate material into good tractive engagement with thetransport means.

It is also a specific object of this invention to provide, in a machinein which discrete lengths of paperboard or the like must be advancedalong a defined path in edge-to-edge abutting relationship, means forachieving and maintaining such edgewise abutment as the lengths ofmaterial are advanced along the path, and for preventing the lengths ofmaterial from overriding and overlapping one another as well as forpreventing them from separating or spreading into spaced apartrelationship.

Another specific object of this invention is to provide simple means ina skin packaging machine for preventing rolling displacement of articlesto be packaged that have been deposited onto substrate material as itmoves through the machine, thereby assuring that such articles willremain in predetermined positions relative to one another and to thesubstrate material.

With these observations and objectives in mind, the manner in which theinvention achieves its purpose will be appreciated from the followingdescription and the accompanying drawings, which exemplify theinvention, it being understood that such changes in the specificapparatus disclosed herein may be made as come within the scope of theappended claims.

The accompanying drawings illustrate one complete example of theembodiment of the invention constructed according to the best mode sofar devised for the practical application of the principles thereof, andin which:

FIG. 1 is a more or less diagrammatic perspective view of a portionof askin packaging machine embodying the principles of this invention, andparticularly of the means by which discrete lengths of substrate arebrought into edgewise abutting relationship;

FIG. 2 is a view in vertical section, on an enlarged scale, ofsubstantially the portion of the machine that is shown in FIG.

FIG. 3 is a sectional view taken on the plane of the line 33 in FIG. 2;

FIG. 4 is a plan view of portions of the machine in the neighborhood ofthe film applying station, with parts s'hown broken away to illustratedetails of construction;

FIG. 5 is a sectional view taken on the plane of the line 5-5 in FIG. 4;

FIG. 6 is a sectional view taken on the plane of the line 6-6 in FIG. 4;

FIG. 7 is a sectional view taken on the plane of the line 7 -7 in FIG.6; and

FIG. 8 is a diagrammatic perspective view of the means for holdingarticles to be packaged by the machine against displacement out of theirdesired locations on the substrate as the substrate is moving toward thefilm applying station;

FIG. 9 is a fragmentary perspective view of the conveyor beltillustrating a feature which may be employed to facilitate strippingaccidentally deposited plastic film from the belt.

Referring now to the accompanying drawings, the numeral 5 designatesgenerally a skin packaging machine in which substrate material 6 isadvanced along a defined generally horizontal path that carries it pasta loading station 7 (indicated in broken lines in FIG. 4) at whicharticles 8 to be packaged are deposited upon it, and then past a station9 (also indicated in broken lines in FIG. 4) at which a film ofthermoplastic substance is deposited over each article and at least thatportion of the upper surface of the substrate that surrounds thearticle.

The substrate material comprises precut rectangular lengths or panels ofpaperboard or the like, which may be individual cards, one for eacharticle, or can be long enough to comprise several packages and to becut transversely into a number of identical cards. It will be apparentas the description proceeds that the mechanism herein disclosed couldoperate equally well with substrate material in continuous web form,drawn from a roll thereof.

As the substrate material moves downstream past the load ing station 7,the articles 8 are successively deposited onto it at spaced intervalsalong it, each article being so disposed that it will occupy a centralportion of one of the cards into which the panel is to be cut. Theloading station 7 can be of any conventional type by which articles areconducted down toward the substrate from a level above the same and aredeposited onto the substrate at uniform time intervals. It will beapparent from the principles of this invention are applicable tomachines in which articles are loaded manually, and also to thoseintended merely for applying a coating of film or the like to asubstrate.

The film applying station 9 can be of the type disclosed in the abovementioned application Ser. No. 842,99l, to which reference can be madefor further details. In any event it comprises a nozzle (not shown) fromwhich molten thermoplastic substance issues to coat the articles and thetop surface of the substrate material.

The means for advancing substrate downstream through the machinecomprises an endless flat belt 12 and rollers 13 around which it istrained. The rollers are rotatably mounted on an elongated machine frame14 with their axes horizontal and transverse to the path along which thesubstrate advances, and they are spaced apart a substantial distancealong said path to provide an elongated straight upper stretch 15 of thebelt. To drive the belt so that its upper stretch will move in thedownstream direction, at least the roller 13 at the downstream end ofthe upper stretch is driven by an electric motor (not shown) or similarpower means, through a suitable transmis- 81011.

As it moves, the upper stretch of the belt passes in succession over asuction manifold 16 and a vacuum table 17, both of which are supportedby the machine frame 14 between the rollers 13. The suction manifold 16extends lengthwise of the upper belt stretch from near the upstreamroller 13, past the loading station 7, to a point adjacent to the vacuumtable 17.

The belt has a pattern of grooves opening to its outer surface, whichprovides mouths through which the suction in the manifold 16 and in thevacuum table 17 is applied to the underside of substrate on the upperstretch of the belt. Across one-half of the width of the belt thesegrooves, designated 20t,

are oriented transversely of the belt and extend from near one edge ofthe belt (which for convenience may be considered its rear edge) toalmost the middle of the belt. In the other half of the belt width, thegrooves, designated 20L, extend lengthwise of the belt and are dividedinto successive ranks.

Holes 22 through the bottoms of the transverse grooves 20t near theinner ends thereof register with elongated slots 23 in the top of themanifold 16 so that as these grooves travel along the length of themanifold the suction therein will be manifested at the underside ofsubstrate on the belt. Obviously as the hole 22 of each transversegroove comes into register with a slot 23, the entire length of thegroove becomes a suction mouth so that substrate on the belt will betightly held thereto regardless of its width.

The width of the belt of course determines the maximum width ofsubstrate that can be handled by the machine; its minimum width isdetermined by the length of the transverse grooves. This follows fromthe fact that the substrate is always fed to the belt with one side edgethereof closely adjacent to the rear edge of the belt, it beingunderstood that the width of the substrate must not be less than thelength of the transverse grooves.

The longitudinal grooves have holes 24 through the bottom thereof bywhich they are communicated with suction manifested in the vacuum table17, and since the holes 22 in the bottom of the transverse grooves alsocommunicate with the vacuum table as they traverse the same, the vacuumtable can apply suction to the underside of the substrate across theentire width thereof.

The vacuum table is essentially a flat metal slab 25 fixed to themachine frame with its top surface contiguous to the underside of thetop stretch of the belt. A grid-like air intake opening to the topsurface of the slab provides for suction to be manifested at theunderside of the belt as it traverses the vacuum table. This grid-likeair intake comprises three sets or groups of lengthwise extendinggrooves 26 which are laterally spaced apart by distances correspondingto the spacing between the longitudinal grooves 20L in the belt, andanother lengthwise extending groove 27 positioned to align with theholes 22 in the transverse grooves 20!. For each set or group of grooves26 there is a suction manifold 29 in the form of a transverse borethrough the slab 25. The manifolds are connected with a suction sourcethrough ducts 30, and to commu nicate the grooves 26 as well as thegroove 27 with the manifolds, all of the grooves are deep enough tointersect the upper portions of the bores that form the manifolds. Hencesuction in the manifolds are not blocked between the grooves and thesource of suction. Thus by providing adjustable closures for the bores,the effective width of the grid-like air intake can be correlated to anygiven width of substrate between minimum and maximum. Inasmuch as theminimum width of substrate for which the machine is designed, issomewhat greater than the length of transverse grooves 201, the groove27 is never cut off from communication with the manifolds, butcommunication of the grooves 26 with the manifolds is controllable bypiston-like plugs 31 that are slidably received in the bores.

The plugs 31 are formed or rubber or neoprene, and as shown in FIG. 6,are confined between the inner end ofa tube 32 and the head 33 of ascrew threaded rod 34 that extends through the tube and has a knurledadjusting nut 35 threaded thereon and bearing against the outer end ofthe tube. Obviously by adjustment of the nut, the diameter of the plugcan be increased or decreased, as needed to give the same a smoothsliding air tight fit in the manifold. Adjustment of the plugs to closeoff those of the grooves 20L that are not covered by substrate, isfacilitated by knobs 36 secured to the outer ends of the rods 34.

The suction manifold 16 comprises a square tube extending lengthwise ofthe belt. lts opposite ends are plugged and it is connected in anysuitable manner with a source of suction. The flat top surface of thetube upon which the longitudinally medial portion of the upper beltstretch rides, has the lengthwise extending air intake slots 23 formedtherein to register with the holes 22 in the belt.

Where the upper stretch of the belt rides on the narrow suctionmanifold, its laterally outer portions are supported by idler rollers 37that are mounted on the machine frame at lengthwise spaced intervals.These rollers are upwardly tangent to a plane that lies slightly belowthe level of the top surface of the suction manifold, to insure that thebelt will have good sealing engagement with the suction manifold as itslides therealong.

It will be apparent that the application of a good suction to substratematerial on the belt is dependent upon there being no substantial gapsor breaks along the length of the substrate material that would offer alarge opening through which air could freely enter the air intakes ofthe suction manifold or vacuum table.

The means for insuring that adjacent precut lengths of substratematerial will move along the upper stretch of the belt in edgewiseabutting relationship comprises, in general, a feed table 39 which hasits discharge end portion overlying the upstream end of the upper beltstretch 15. A notch 40 is formed in the discharge end portion of thefeed table. The side edges of this notch provide a pair of rail-likesupports 41 which coact with a hold-down finger 42 to impart atransverse upwardly concave arcuate curvature to each length ofsubstrate as it leaves the feed table, which, curvature, as will bedescribed, assures against overlapping of successive lengths ofsubstrate.

The feed table serves to carry panels of substrate material toward thebelt from a sheet feeding station at the upstream end of the machine,where individual panels or lengths of precut substrate material areloaded onto the feed table oneby-one, either manually or by means of aconventional sheet feeding mechanism. The panels are forwarded along thefeed table in lengthwise spaced apart relation by one or more sets ofnip rolls 44 which are spaced upstream from the hold down finger 42. Thenip rolls comprise a lower driven roller 45 which projects up through anaperture in the feed table to be upwardly tangent to a plane veryslightly above that of the feed table surface, and a cooperating idlerroller 46 above the driven roller. The driven roller 45, which can bedrivingly connected by means of a belt or chain 47 with the upstreambelt roller 13, tends to forward the substrate material at a speedfaster than the rate of belt advance, but it has a smooth peripheralsurface and can therefore slip on the substrate to some extent. Theidler roller 46 has limited up and down motion, and is biased downwardlyby a spring 48 to hold the substrate material in tractive engagementwith the driven roller, By adjustment of the spring any desired degreeof slippage between the driven roller and the substrate can be had.

Parallel fixed and adjustable guide rails 49 and 50 extending lengthwisealong the feed table engage the opposite side edges of the substrate toposition it accurately across the width of the table and hold itstraight. Since the narrowest substrate for which the machine isdesigned must overlie the transverse grooves 20t in the belt, the fixedguide rail is at the rear edge of the feed table, and it will beunderstood that the location of the adjustable rail is determined by thewidth of the substrate.

Adjustment of the rail 50 can be effected in any suitable,

manner.

The top surface of the feed table and hence the rail-like supports 41provided by the side edges of the notch 40 in the feed table areelevated a small distance above the upper stretch of the belt, but thehold down finger 42, in the absence of substrate therebeneath, rides onthe belt.

The hold-down finger is essentially a bar that extends lengthwise in thedirection of substrate advance between the rail-like supports 41. Itdepends from a bracket 55 which is carried by the machine frame andextends over the belt from one side thereof. A pair of pins 56 projectupwardly from the hold down finger, one near each end of it, and areslidably received in the bracket 55 to provide for limited up and downtranslatory and tilting motion of the finger. A coiled compressionspring 57 on the front one of these pins reacts between the bracket andthe finger to bias the downstream end of the latter downwardly towardthe belt. The upstream end portion of the hold down finger has itsunderside chamfered or curved to facilitate its riding up onto anadvancing length of substrate.

As best seen in FIG. 3, the hold-down finger engages the advancingsubstrate panel only along a lengthwise narrow zone between therail-like supports 41, and in so doing presses this portion of the paneldown below the level of the top surface of the feed table and onto thebelt. The side edge portions of the panels are of course held at ahigher level by the supports 41. Thus, as indicated, the hold-downfinger cooperates with these supports to impart to the substrate atransverse upwardly concave arcuate curvature by which a medial portionthereof is disposed below the level of the top surface of the feed tablewhile marginal side edge portions thereof extend substantially I abovethat level.

As each piece of panel of substrate material moves off the feed tableand under the hold-down finger, its medial portion is engaged with thebelt all along its length, and its trailing portion retains thetransverse curvature just described until it leaves the rail-likesupports 41. But before it does so the leading edge of the succeedingpanel of substrate collides with the arcuately curved rear edge of thepiece on the belt. Until the succeeding piece comes under the hold-downfinger, it of course remains fiat, and therefore its straight front edgeengages the bowed rear edge of the preceding panel at two spaced points,thus assuring edgewise abutment of the two panels and preventing thefollowing one from overriding or underriding the leading one.

Until the succeeding piece or panel moves all the way under thehold-down finger, and into full tractive engagement with the belt (stillin edgewise relationship to the panel ahead of it) its rear end portiondoes not pass out of the nip rolls which continue their tendency toadvance the panel at a speed faster than that of the belt, and thusassures its edgewise abutting engagement with the panel ahead of it.

To give a signal which will initiate a cycle of sheet feeder operationor notify an attendant that a panel must be manually placed on the feedtable, a limit switch 64 is' located downstream from the nip rolls. Itis held open by substrate beneath it and closes when the trailing edgeof a length of substrate passes out from under it. The provision of thisswitch insures that a length of substrate will not arrive at thehold-down finger too late to catch up with the panel of substrate aheadof it.

As the panels of substrate move along downstream from the hold-downfinger, the articles to be packaged are placed on them at the loadingstation 7. If the articles are cylindrical (as for example flashlightcases) they would have a tendency to roll toward one edge or the otherof the substrate, owing to the fact that the upper belt stretch has aslight hump along its medial portion where it rides on the suctionmanifold. To prevent such rolling of cylindrical articles that aremagnetizable, a magnet 65 is mounted beneath the belt, having oppositepole shoes at opposite sides of the suction manifold. The pole shoes areelongated, or a plurality of downstream adjacent magnets can be used, sothat the magnetic field produced thereby extends from the loadingstation at least to the downstream end of the suction manifold, andpreferably a short distance past the film applying station.

The magnetic field produced by the magnet means holds the articlescentered between the magnet poles and thus prevents the articles fromrolling toward either edge of the belt. Once an article passes the filmapplying station 9, the film overlying it tends to hold the articleagainst rolling, and therefore the magnet means need not extend anysubstantial distance downstream from the film applying station.

Although it is not intended that the molten thermoplastic be extrudedfrom the nozzle at the film applying station 9, unless the conveyor beltis covered by substrate a malfunction of the sheet feeder may result inthe molten plastic being discharged on to the uncovered surface of thebelt. If that happens a plastic ribbon is formed which has atransversely undulated shape imparted thereto due to the transversegrooves in the belt. This undulated shape makes it difficult to stripthe plastic ribbon from the belt, especially when minimum widthsubstrate is being used. The tendency for the undulated ribbon tostretch like an accordion interfered with its removal from the belt.

The slight modification of the belt illustrated in FIG. 9, greatlyminimizes this objection. By virtue of localized raised portions 60 thatrise from the bottom of the transverse grooves 20t at spaced intervalsalong the length thereof, bridging ribs are formed across theundulations in an accidentally applied plastic ribbon, which resistaccordion-like stretching. As shown, the tops of the raised portions areslightly below the outer surface of the belt so that despite theirpresence, the single hole 22 in each groove communicates the entirelength thereof with the suction source.

From the foregoing description taken with the accompanying drawings itwill be apparent that this invention provides means in a film coatingmachine for applying suction to the underside of substrate material uponwhich thermoplastic film is deposited, and for moving precut lengths ofsubstrate material downstream through the machine in edgewise abuttingrelationship so that there no gaps between the lengths through whichsuction can be lost. It will also be apparent that the invention adaptsthe machine for use with substrate materials of different widths and foruse with substrate in continuous web form as well as in precut lengths.

Those skilled in the art will appreciate that the invention can beembodied in forms other than as herein disclosed for purposes ofillustration.

The invention is defined by the following claims.

lclaim:

1. In a packaging machine having a plurality of stations along a definedpath, at one of which heated thermoplastic material is applied tosubstrate material and articles disposed thereon to form a film overeach article and a portion of the substrate top surface that surroundsit, means for advancing substrate material with articles thereon fromone to another of said stations and for applying suction to the bottomof the substrate material to suck the film down into snug engagementwith the articles and the top surface of the substrate, the last namedmeans comprising:

A. a vacuum table which has 1; an upwardly facing stationary top surfacethat is interrupted by a plurality of spaced apart air inlet openingswhich collectively form a station-ary air intake, and 2. manifold meanscommunicating with said openings;

B. an endless flat belt having an upper stretch which fiatwise overliesand slides lengthwise across said stationary top surface of the vacuumtable, said belt having apertures therethrough which register with saidstationary air inlet openings as the belt travels across the vacuumtable; and

C. means for applying suction to said manifold means, which suction isapplied to substrate material riding on the belt as the apertures in thebelt are brought into communication with said stationary air inletopenings, to cause the substrate material to tractively adhere to theupper stretch of the belt for advancement therewith and to draw airthrough the substrate material and thus evacuate the space beneath filmthereon.

2. The packaging machine of claim 1, further characterized by meansadapting the machine for use with discrete lengths of substratematerial, the last mentioned means comprising:

D. means defining a feed table having its discharge end substantiallyover the upstream end of the top stretch-of the belt;

E. means for successively feeding discrete lengths of substrate materialalong said feed table off its discharge end and towards the belt at aspeed which tends to be faster than that at which the top stretch of thebelt travels; and

F. means at the discharge end of the feed table for imparting atransversely bowed shape to the trailing end of each length of substratematerial as it leaves the feed table by which the next successive lengthof substrate material is prevented from overlapping it and is thusforced into edgewise abutting relation to it.

3. The packaging machine of claim 2, wherein said means for imparting abowed shape to the trailing end of each length of substrate comprises:

G. substantially parallel longitudinal supports at the discharge end ofthe feed table spaced apart transversely of the belt and formingextensions of the feed table substantially parallel to the top surfaceof said stretch of the belt but elevated above the same; and

H. hold down means between said spaced apart longitudinal supports forforcing a medial portion of the substrate material downwardly below thelevel of said longitudinal supports.

4. The packaging machine of claim 3, wherein said hold down means isabove the top stretch of the belt and biased downwardly to force thesubstrate material into tractive engagement with the top stretch of thebelt.

5. The packaging machine of claim 1, wherein said stationary inlet airopenings in the top surface of the vacuum table comprise lengthwiseextending transversely spaced grooves opening to its upwardly facingsurface, and wherein said manifold means comprises:

A. a transverse bore intersected by said grooves and communicable at oneend with a source of suction;

B. a plug axially slidable in said bore to block communication between aselected number of said grooves and the source of suction to therebyadapt the vacuum table to different widths of substrate material withoutloss of suction; and

C. plug adjusting means connected to the plug and protruding from theother end of the bore.

6. In a packaging machine in which substrate material and articles to bepackaged that are disposed thereon are carried in one direction along adefined path past a station at which heated thermoplastic material isapplied to the articles and the substrate material to form a film overthe same, means for moving substrate material along said defined pathand for sucking film down into snug engagement with each article andwith its surrounding portion of the substrate material, the lastmentioned means comprising:

A. a flat endless belt which is at least as wide as the substratematerial and which has apertures thereth rough at longitudinally andlaterally spaced intervals;

B. roller means around which the belt is trained with a straight stretchthereof uppermost and extending along said defined path and which drivesthe belt for movement in said direction; and

C. air intake means between the roller means, having a stationaryapertured top surface along which the upper stretch of the belt extendsand with which it has intimate fiatwise supporting engagement, theapertures in said surface of the air intake means being so arranged thatthe apertures in the belt register with them to enable air to be 'drawninto the air intake means through the apertures in the belt and throughsubstrate material on the belt.

7. The packaging machine of claim 6, further characterized by:

said apertures in the belt being defined by grooves in the outer surfaceof the belt, and holes through the bottom of at least some of thegrooves.

8. The packaging machine of claim 7, wherein said holes in the belt arealigned in rows that extend parallel to the edges of the belt and arespaced transversely thereacross, further characterized by said aperturesin the air intake means being defined by:

1. grooves that open to the top surface of the air intake means andextend lengthwise in said direction, said grooves being spaced apartlaterally in correspondence with the transverse spacing of said holes inthe belt so that the holes in the belt register with the grooves in theair intake means; and

2. the air intake means having a bore that extends transversely to saidgrooves therein and opens to them, which bore is connectable with asource of suction and thus provides for communication of said groovestherewith.

9. The packaging machine of claim 6, further characterized by meansadapting the machine for use with discrete lengths of substratematerial, the last mentioned means comprising:

A. a feed table having its discharge end substantially over the upstreamend of said stretch of the belt;

B. hold down means adjacent to the discharge end of the feed table andabove the receiving end portion of said stretch of the belt to urge thelengths of substrate material into tractive engagement with said stretchof the belt as they leave the feed table; and

C. longitudinally extending horizontal supports spaced laterally of thebelt to opposite sides of the hold down means and substantially coplanarwith the feed table to cooperate with the hold down means to flex thetrailing end portion of each length of substrate material leaving thefeed table into an upwardly concave curvature by which a succeedinglength of such material is prevented from overrunning said length and iscaused to establish edgewise abutting relationship therewith.

10. In a machine in which discrete lengths of a material on the order ofpaperboard are moved in one direction along a defined path past aprocessing station, means for establishing such lengths of material inedge-to-edge abutting relationship and for carrying them along said pathin such relationship, said means comprising:

A. a flat endless belt;

B. roller means around which the belt is trained with a straight stretchthereof uppermost and extending along said path and by which the belt isdriven for movement of said stretch in said direction;

C. a feed table having a surface which is substantially parallel to, butat a level above, said stretch of the belt, and which extends in saiddirection to an edge near said stretch and substantially transversethereto;

D. means for advancing lengths of material in said direction along saidsurface of the feed table and by which such lengths are yieldingly urgedin said direction at a speed which tends to be faster than the speed ofsaid stretch of the belt; E. hold-down finger means above said stretchof the belt and spaced in said direction from said edge, said holddownfinger means being arranged to engage each advancing length of materialat a portion thereof that is between its side edges, and to force thesame down into tractive engagement with said stretch of the belt; and F.means providing a pair of elongated rails which extend lengthwise insaid direction from said edge on the feed table and which are spacedlaterally of the belt to opposite sides of the hold-down finger means,said rails having surfaces substantially coplanar with said surface onsaid table, which surfaces on the rails support side edge portions of alength of material engaged by the hold down finger means and cooperatewith the latter in imparting an upwardly concave curvature to the lengthof material that prevents overrunning of it by a succeeding length ofmaterial and establishes the latter in edgewise abutting engagement withit. 11. The machine of claim 10, further characterized by: G. the belthaving numerous apertures therethrough; and H. a grid-like air intakedisposed beneath said stretch of the belt for flatwise supportingengagement by the same, said air intake being connectable with a sourceof suction for drawing air through the apertures in the belt to thussuck lengths of material on said stretch into tractive engagementtherewith. 12. in a machine in which discrete lengths of a material onthe order of paperboard are moved in one direction along a defined pathpast a processing station, and which machine must at different timesaccommodate lengths of such material that are of different widths, meansfor transporting such lengths of material along said path, comprising:

A. an endless belt having broad inner and outer surfaces and having aplurality of apertures therethrough, each of which apertures is definedby l. an elongated lengthwise extending groove opening to the outersurface of the belt, and

2. a smaller hole opening to the bottom of the groove and to the innersurface of the belt, said apertures being centered on a plurality oflaterally spaced lines that extend parallel to the edges of the belt;

B. roller means around which the belt is trained and by which it isdriven, providing a straight upper stretch of the belt which extendsalong said path and moves in said direction;

C. an air intake comprising an element having an upper surface by whichsaid stretch of the belt is supportingly engaged, said air intakehaving 1. grooves opening to its said upper surface and extending insaid direction, said grooves being longitudinally centered on linesspaced in correspondence to said lines upon which the apertures in thebelt are centered so that said apertures register with the grooves, and

2. a bore through said element, extending transversely to said groovestherein and opening to each of them, one end of said bore beingconnectable with a suction source so that suction can be applied tolengths of material on said stretch of the belt, to suck them intotractive engagement with the belt, through grooves in the air intakethat are communicated with said bore and apertures in the belt thatregister with said grooves; and

D. a rod-like plug receivable in the bore from the other end thereof toblock communication between the bore and a selected number of grooves inthe air intake, so that air is not drawn through apertures in the beltthat are to one side of lengths of material being transported thereon.

13. The machine of claim 12, further characterized by: said belt havingother apertures therein, nearer the edge thereof that is adjacent to thefirst mentioned end of the bore in the air intake, each of said otherapertures being defined by 1. an elongated groove opening to the outersurface of the belt and extending transversely to the belt edges, and

2. a smaller hole opening to the bottom of each of said other groovesand to the inner surface of the belt,

the last mentioned holes being centered on a line parallel to the edgesof the belt to register with the groove in the air intake that isnearest said first mentioned end of the bore.

14. The machine of claim 13, wherein said processing station comprisesmeans for applying molten thermoplastic to the lengths of material beingprocessed, further characterized by:

each of said transverse grooves in the belt having a locally

1. In a packaging machine having a plurality of stations along a definedpath, at one of which heated thermoplastic material is applied tosubstrate material and articles disposed thereon to form a film overeach article and a portion of the substrate top surface that surroundsit, means for advancing substrate material with articles thereon fromone to another of said stations and for applying suction to the bottomof the substrate material to suck the film down into snug engagementwith the articles and the top surface of the substrate, the last namedmeans comprising: A. a vacuum table which has
 1. an upwardly facingstationary top surface that is interrupted by a plurality of spacedapart air inlet openings which collectively form a station-ary airintake, and
 2. manifold means communicating with said openings; B. anendless flat belt having an upper stretch which flatwise overlies andslides lengthwise across said stationary top surface of the vacuumtable, said belt having apertures therethrough which register with saidstationary air inlet openings as the belt travels across the vacuumtable; and C. means for applying suction to said manifold means, whichsuction is applied to substrate material riding on the belt as theapertures in the belt are brought into communication with saidstationary air inlet openings, to cause the substrate material totractively adhere to the upper stretch of the belt for advancementtherewith and to draw air through the substrate material and thusevacuate the space beneath film thereon.
 2. manifold means communicatingwith said openings; B. an endless flat belt having an upper stretchwhich flatwise overlies and slides lengthwise across said stationary topsurface of the vacuum table, said belt having apertures therethroughwhich register with said stationary air inlet openings as the belttravels across the vacuum table; and C. means for applying suction tosaid manifold means, which suction is applied to substrate materialriding on the belt as the apertures in the belt are brought intocommunication with said stationary air inlet openings, to cause thesubstrate material to tractively adhere to the upper stretch of the beltfor advancement therewith and to draw air through the substrate materialand thus evacuate the space beneath film thereon.
 2. The packagingmachine of claim 1, further characterized by means adapting the machinefor use with discrete lengths of substrate material, the last mentionedmeans comprising: D. means defining a feed table having its dischargeend substantially over the upstream end of the top stretch of the belt;E. means for successively feeding discrete lengths of substrate materialalong said feed table off its discharge end and towards the belt at aspeed which tends to be faster than that at which the top stretch of thebelt travels; and F. mEans at the discharge end of the feed table forimparting a transversely bowed shape to the trailing end of each lengthof substrate material as it leaves the feed table by which the nextsuccessive length of substrate material is prevented from overlapping itand is thus forced into edgewise abutting relation to it.
 2. the airintake means haVing a bore that extends transversely to said groovestherein and opens to them, which bore is connectable with a source ofsuction and thus provides for communication of said grooves therewith.2. a smaller hole opening to the bottom of the groove and to the innersurface of the belt, said apertures being centered on a plurality oflaterally spaced lines that extend parallel to the edges of the belt; B.roller means around which the belt is trained and by which it is driven,providing a straight upper stretch of the belt which extends along saidpath and moves in said direction; C. an air intake comprising an elementhaving an upper surface by which said stretch of the belt issupportingly engaged, said air intake having
 2. a bore through saidelement, extending transversely to said grooves therein and opening toeach of them, one end of said bore being connectable with a suctionsource so that suction can be applied to lengths of material on saidstretch of the belt, to suck them into tractive engagement with thebelt, through grooves in the air intake that are communicated with saidbore and apertures in the belt that register with said grooves; and D. arod-like plug receivable in the bore from the other end thereof to blockcommunication between the bore and a selected number of grooves in theair intake, so that air is not drawn through apertures in the belt thatare to one side of lengths of material being transported thereon.
 2. asmaller hole opening to the bottom of each of said other grooves and tothe inner surface of the belt, the last mentioned holes being centeredon a line parallel to the edges of the belt to register with the groovein the air intake that is nearest said first mentioned end of the bore.3. The packaging machine of claim 2, wherein said means for imparting abowed shape to the trailing end of each length of substrate comprises:G. substantially parallel longitudinal supports at the discharge end ofthe feed table spaced apart transversely of the belt and formingextensions of the feed table substantially parallel to the top surfaceof said stretch of the belt but elevated above the same; and H. holddown means between said spaced apart longitudinal supports for forcing amedial portion of the substrate material downwardly below the level ofsaid longitudinal supports.
 4. The packaging machine of claim 3, whereinsaid hold down means is above the top stretch of the belt and biaseddownwardly to force the substrate material into tractive engagement withthe top stretch of the belt.
 5. The packaging machine of claim 1,wherein said stationary inlet air openings in the top surface of thevacuum table comprise lengthwise extending transversely spaced groovesopening to its upwardly facing surface, and wherein said manifold meanscomprises: A. a transverse bore intersected by said grooves andcommunicable at one end with a source of suction; B. a plug axiallyslidable in said bore to block communication between a selected numberof said grooves and the source of suction to thereby adapt the vacuumtable to different widths of substrate material without loss of suction;and C. plug adjusting means connected to the plug and protruding fromthe other end of the bore.
 6. In a packaging machine in which substratematerial and articles to be packaged that are disposed thereon arecarried in one direction along a defined path past a station at whichheated thermoplastic material is applied to the articles and thesubstrate material to form a film over the same, means for movingsubstrate material along said defined path and for sucking film downinto snug engagement with each article and with its surrounding portionof the substrate material, the last mentioned means comprising: A. aflat endless belt which is at least as wide as the substrate materialand which has apertures therethrough at longitudinally and laterallyspaced intervals; B. roller means around which the belt is trained witha straight stretch thereof uppermost and extending along said definedpath and which drives the belt for movement in said direction; and C.air intake means between the roller means, having a stationary aperturedtop surface along which the upper stretch of the belt extends and withwhich it has intimate flatwise supporting engagement, the apertures insaid surface of the air intake means being so arranged that theapertures in the belt register with them to enable air to be drawn intothe air intake means through the apertures in the belt and throughsubstrate material on the belt.
 7. The packaging machine of claim 6,further characterized by: said apertures in the belt being defined bygrooves in the outer surface of the belt, and holes through the bottomof at least some of the grooves.
 8. The packaging machine of claim 7,wherein said holes in the belt are aligned in rows that extend parallelto the edges of the belt and are spaced transversely thereacross,further characterized by said apertures in the air intake means beingdefined by:
 9. The packaging machine of claim 6, further characterizedby means adapting the machine for use with discrete lengths of substratematerial, the last mentioned means comprising: A. a feed table havingits discharge end substantially over the upstream end of said stretch ofthe belt; B. hold down means adjacent to the discharge end of the feedtable and above the receiving end portion of said stretch of the belt tourge the lengths of substrate material into tractive engagement withsaid stretch of the belt as they leave the feed table; and C.longitudinally extending horizontal supports spaced laterally of thebelt to opposite sides of the hold down means and substantially coplanarwith the feed table to cooperate with the hold down means to flex thetrailing end portion of each length of substrate material leaving thefeed table into an upwardly concave curvature by which a succeedinglength of such material is prevented from overrunning said length and iscaused to establish edgewise abutting relationship therewith.
 10. In amachine in which discrete lengths of a material on the order ofpaperboard are moved in one direction along a defined path past aprocessing station, means for establishing such lengths of material inedge-to-edge abutting relationship and for carrying them along said pathin such relationship, said means comprising: A. a flat endless belt; B.roller means around which the belt is trained with a straight stretchthereof uppermost and extending along said path and by which the belt isdriven for movement of said stretch in said direction; C. a feed tablehaving a surface which is substantially parallel to, but at a levelabove, said stretch of the belt, and which extends in said direction toan edge near said stretch and substantially transverse thereto; D. meansfor advancing lengths of material in said direction along said surfaceof the feed table and by which such lengths are yieldingly urged in saiddirection at a speed which tends to be faster than the speed of saidstretch of the belt; E. hold-down finger means above said stretch of thebelt and spaced in said direction from said edge, said hold-down fingermeans being arranged to engage each advancing length of material at aportion thereof that is between its side edges, and to force the samedown into tractive engagement with said stretch of the belt; and F.means providing a pair of elongated rails which extend lengthwise insaid direction from said edge on the feed table and which are spacedlaterally of the belt to opposite sides of the hold-down finger means,said rails having surfaces substantially coplanar with said surface onsaid table, which surfaces on the rails support side edge portions of alength of material engaged by the hold-down finger means and cooperatewith the latter in imparting an upwardly concave curvature to the lengthof material that prevents overrunning of it by a succeeding length ofmaterial and establishes the latter in edgewise abutting engagement withit.
 11. The machine of claim 10, further characterized by: G. the belthaving numerous apertures therethrough; and H. a grid-like air intakedisposed beneath said stretch of the belt for flatwise supportingengagement by the same, said air intake being connectable with a sourceof suction for drawing air through the apertures in the belt to thussuck lengths of material on said stretch into tractive engagementtherewith.
 12. In a machine in which discrete lengths of a material onthe order of paperboard are moved in one direction along a defined pathpast a processing station, and which machine must at different timesaccommodate lengths of such material that are of different widths, meansfor transporting such lengths of mateRial along said path, comprising:A. an endless belt having broad inner and outer surfaces and having aplurality of apertures therethrough, each of which apertures is definedby
 13. The machine of claim 12, further characterized by: said belthaving other apertures therein, nearer the edge thereof that is adjacentto the first mentioned end of the bore in the air intake, each of saidother apertures being defined by
 14. The machine of claim 13, whereinsaid processing station comprises means for applying moltenthermoplastic to the lengths of material being processed, furthercharacterized by: each of said transverse grooves in the belt having alocally raised portion rising from its bottom, intermediate its ends, sothat thermoplastic which unintentionally may accumulate on the belt andharden into a thin ribbon with an undulated formation caused by thetransverse grooves, has bridging ribs formed therein across theundulations, which ribs prevent the undulated ribbon of hardenedthermoplastic from stretching accordion-wise as it is stripped off thebelt.